Knee brace



FIG. 1 is an enlarged perspective view of a knee brace;

FIG. 2 is an enlarged left view of thereof;

FIG. 3 is an enlarged rear view thereof; and

FIG. 4 is a bottom view thereof; and,

FIG. 5 is a top view thereof.

All other broken lines depict portions of the knee brace and form no part of the claim. 

CLAIM I claim the ornamental design for a knee brace, as shown and described. 